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FAST TESTS CAN CATCH CONTAMINATION AT PLANT

WHILE DISAGREEMENT AMONG EXPERTS AND, TO A LESSER EXTENT, VESTED INTERESTS ON HOW BEST TO DEFINE A "QUALITY" ASPHALT ENCUMBERS CONTRACTOR QUALITY CONTROL TESTING, IT HAS LITTLE EFFECT ON DEFINITION AND IDENTIFICATION OF CONTAMINATION ARISING FROM INADVERTENT MISTAKES AT THE REFINERY, AT THE TERMINAL, OR IN TRANSPORT. THERE ARE TWO RAPID TESTS THAT THE CONTRACTOR CAN USE TO PREVENT CONTAMINATED MATERIAL FROM GETTING INTO HIS WORKING TANKS. EACH CAN BE RUN IN ABOUT 15 MINUTES BY AN ORDINARY PLANT TECHNICAIAN ON THE SITE. THE STANDARD METHOD OF TESTING FOR "FLASH AND FIRE POINTS BY CLEVELAND OPEN CUP" IS ASTM D-92-66 AND AASHO NO. T-48. HOWEVER, THE SLOW TEMPRATURE RISE CALLED FOR IN THOSE SPECIFICATIONS IS UNNECESSARY WHEN ONLY CONTAMINATION IS BEING TESTED. A RECOMMENDED RAPID PROCEDURE IS DESCRIBED IN DETAIL. THE STANDARD PENETRATION TESTS (ASTM D-5-65 OR AASHO T-49) REQUIRE CONTROLLED CONDITIONS AND TAKE 2--3 HOURS TO PERFORM. BY SPEEDING THE COOLING OF THE SAMPLE TO 77 F AND USING A SMALLER SAMPLE, IT IS POSSIBLE TO OBTAIN AN APPROXIMATION OF THE PENETRATION THAT IS ACCURATE ENOUGH TO DETECT CONTAMINATION OR, IN MOST CASES, TO DETERMINE WHETHER THE CORRECT PENETRATION GRADE HAS BEEN SHIPPED. THE PROCEDURE FOR THE FAST PENETRATION TEST IS DESCRIBED. AN ALTERNATIVE IS THE ASPHALT INSTITUTE MODIFICATION OF THE FORD CUP, DEVELOPED BY V. P. PUZINAUSKAS (THE PUZINAUSKAS--ASPHALT INSTITUTE VISCOMETER). THIS METHOD IS MORE ACCURATE THAN THE FAST PENETRATION TEST AND CAN BE RUN IN A SHORTER TIME. ITS DISADVANTAGES ARE THAT THE TECHNICIAN MUST EITHER CLIMB UP ON THE TANK WAGON AND WORK THROUGH THE MANHEAD, OR DRAW ABOUT A 5-GALLON SAMPLE. THE INSTRUMENT IS ALSO A BIT DIFFICULT TO CLEAN AND DEPENDS ON THE SUPPLIER FOR THE CORRECT VISCOCITY-- TEMPERATURE RELATIONSHIP. IT IS RECOMMENDED THAT BOTH THE CLEVELAND OPEN CUP AND EITHER OF THE TWO OTHER METHODS BE USED TO DETECT CONTAMINATION.